Oil seal diaphragm



1960 E. L. SCHLAGE 2,950,499

011. SEVAL DIAPHRAGM Filed Jan. '7, 1957 1N VEN TOR. ERNEST L. SCHLAGE ATTORNEYS 011.. SEAL DIAPGM Ernest L. Schlage, Burlingame, Calif., assignor to Schlage Lock Company, a corporation Filed Jan. 7, 1957, Ser. No. 632,860

2 Claims. (CI. 16-51) This invention relates to a sealing diaphragm for effecting an oil seal between two members supported for oscillation relative to each other.

In many instances, and especially in hydraulic door closers it is necessary to effect a seal between a shaft and the bearing or other mount in which it oscillates or rotates. In the case of door closers which undergo long periods of use without attention it has been almost impossible to employ stufiing boxes or other types of seals that do not eventually leak after a long period of use. Although various types of seals are available to reduce oil leakage a slight amount of leakage is not objectionable in most instances. However, even a slight amount of leakage from a door closer is objectionable because the presence of oil on a floor near a door usually presents a hazard to safety aside from the unsightliness of such oil on the door closer or on the floor.

The main object of the present invention is the provision of an oil seal that is absolutely effective in preventing oil leakage past a shaft mounted for oscillation or rotation.

Another object of the invention is the provision of a novel oil seal that is particularly adapted for use with a door closer installation wherein any leakage whatsoever is objectionable.

In the usual hydraulic door closer there is provided a shaft that extends through the housing and is secured to the door closer linkage that is in turn operatively connected to either the door or the door surround. Said shaft and the piston mechanism to which it is operatively connected is normally designed so that the shaft rotates only about one-half revolution in one direction and then returns to its initial position. The present invention is adapted for use in such an installation wherein the shaft reverses its direction and is not suitable for use with a shaft which rotates in the same direction without reversal.

Fig. l is a top plan view of an hydraulic door closer installation illustrating one application of the invention.

Fig. 2 is an enlarged fragmentary cross section through the door closer shaft as taken along lines 2-2 of Fig. 1 and with the door closer arm removed.

Fig. 3 is a framentary top plan view of the structure of Fig. 2 with the shaft shown in section.

Fig. 4 is a perspective of one form of the diaphragm of the invention.

In detail, and with reference to Fig. 1, the invention will be described in connection with a door closer generally designated 1 and secured to a door 2. Extending outwardly of the door closer from one side thereof is a shaft 3 that is connected to an arm 4. At its outer end arm 4 is pivotally connected as at 5 to a link 6 which in turn is connected at its opposite end as at 7 to the door frame. The door closer structure referred to above may be seen in 11.3. Patent No. 2,723,416, dated November 15, 1955.

The familiar operation of the door closer is such that upon opening movement of the door the arm 4 attached atent O 2,950,499 Patented Aug. 30, 1960 to shaft 3 swings about a third of a revolution relative to the door closer as indicated in dotted lines in Fig. 1. Assuming the door closer remains stationary, the new position of the arm 4 relative thereto is as indicated in dot-dash lines in Fig. 1.

It is pertinent to note that, although shaft 3 oscillates only a fraction of a revolution, it is possible to employ the present invention with a shaft that rotates more than a revolution so long as it ultimately reverses and does not continue to rotate indefinitely in the same direction.

The shaft 3 is integral with a piston (not shown) within the door closer housing and although the presence of oil under high pressure on shaft 3 may be avoided by proper design, some low pressure oil is usually present around the shaft and it is necessary to prevent escape of such oil past the shaft 3.

Referring now to Fig. 2, the shaft 3 is rotatably supported at one end on a suitable hearing such as the sleeve bearing indicated at 10. It will be understood that the opposite end of the shaft 3 is similarly supported and sealed in the manner to be described.

Sleeve 10 is in turn supported in the housing or body 11 of the door closer or may be supported on a removable cap that is in turn secured to the housing. At any rate, leakage of oil is likely to take place between the shaft 3 and the sleeve bearing 10.

By the present invention, the shaft 3 is preferably provided with a smooth annular groove 12 which is adapted to receive therein the inner marginal portion 13 of an annular diaphragm generally designated 14 (Fig. 4).

Diaphragm 14, which may be formed of relatively thin rubber or neoprene or other imperforate flexible and elastic material is also formed with an outer marginal portion 15 of enlarged cross section spaced radially outwardly from the inner marginal portion 13. Said marginal portions are substantially thicker than the main web portion 16 of the diaphragm and the inner portion 13 is preferably formed so that its cross section is complementary to the radially outwardly opening concave face of annular groove 12 on shaft 3. In addition, the inner marginal portion is formed with a radially outwardly opening annular concave face 17 that is adapted to be engaged by the radially inwardly directed side of a clamping ring 20. The ring 29 is preferably formed relative to the portion 13 so that it may be forced over the axially directed end 21 of said portion to exert a radially inwardly directed force thereon thus effecting an oil tight seal between said portion and the shaft 3.

The outer marginal portion 15 is also enlarged and may be generally circular in cross section and is clamped between the axially directed annular face 2 of the housing 11 and a clamping disc 25 which may be centrally apertured as at 26 to loosely receive shaft 3 therethrough.

The housing 11 may be externally threaded to receive thereon a clamping ring 28 which, when screwed onto the housing engages the clamping disc 25 and presses the same against outer marginal portion 15 so as to clamp the latter between said disc and face 24 of housing 11.

From the above description it will be apparent that leakage is positively prevented by fixed seals between inner marginal portion 13 and shaft 3 and between outer marginal portion 15 and housing 11.

The web 16 between the inner and outer marginal portions of the diaphragm may be formed as shown in Fig. 4 to provide an excess of material by means of a bellowslike fold 30 between the radially spaced inner and outer marginal portions.

When the diaphragm 14 is clamped to the shaft 3 and the housing 11 as described above the web portion 16 may be folded on itself several times to the position shown in Fig. 2 so as to take up less space along the by the dot-dash lines of Fig. 1.

length of the shaft. When thus folded it will be apparent that the shaft 3 may be rotated to a limited extent, with the inner marginal portion 13 of the diaphragm attached thereto, without rupturing the web of said diaphragm. In other words, relative oscillation of the inner and outer marginal portions is permitted because of the flexibility of the web portion 16 attributable not only to the inherent flexibility of the material, but to the folds formed therein.

It will be apparent if the relative oscillation between described when the shaft 3 is in a position corresponding to said central position. In other words, when the door is in its normal closed position the diaphragm 14 is wound up, as it were, in one direction from a neutral position. During the opening movement of the door the diaphragm unwinds to'its neutral position corresponding to the central position of the arm 4 and then winds up'in the opposite direction to the position indicated By installing the diaphragm in this manner the amount of strain to which it is subjected is only one half of what it would be if 'it were installed in a neutral position with the door closed.

-It will be apparent that other means may be devised to provide an excess of material in the web 16 between the inner and outer marginal portions although the method of folding above described is preferred.

It will be obvious that the invention cannot be applied to an installation in which the rotating member rotates continuously in one direction without reversing. However, as applied to installations such as door closers wherein a shaft oscillates to a limited extent from a neutral position, the invention completely obviates any leakage because -the diaphragm is fixedly secured to the relatively moving member.

The above specific description of the invention is not to be taken as restrictive thereof as it is obvious that variations in design may be resorted to without departing from the spirit of the invention.

I claim:

1. In combination with a pair of members of which one member is supported for rotation to a limited extent relative to the other member, means for efiecting a fluid seal to prevent passage of fluid between said members comprising: an imperforate annular diaphragm formed with radially spaced inner and outer circular marginal portions and a flexible intermediate portion of elastic material connecting said marginal portions, said marginal portions being formed thicker than said intermediate portion, means for fixedly but releasably securing said marginal portions to said members respectively in fluid tight relation therewith, said intermediate portion being flexed to provide slack between said marginal portions whereby the flexibility of said intermediate portion permits relau tive rotational movement of said members without rupturing said diaphragm.

2. In combination with a pair of members of which one member is supported for rotation to a limited extent relative to the other member, means for effecting a fluid being formed with bellows to augment such flexibility to permit said relative rotation between said members before said diaphragm is ruptured.

References Cited in the file of this patent UNITED STATES PATENTS 1,383,339 Putnam July 5, 1921 1,704,258 I Morgan Mar. 5, 1929 2,407,757 MacCallum Sept. 17, 1946 

